$ git clone -n https://src.fedoraproject.org/rpms/rpmrebuild.git /var/lib/mock/f45-build-34669-690/root/chroot_tmpdir/scmroot/rpmrebuild
Cloning into '/var/lib/mock/f45-build-34669-690/root/chroot_tmpdir/scmroot/rpmrebuild'...
$ git fetch origin 0702af4e71b93c9426d81a4ee4696101c7d62a84:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rpmrebuild
 * [new ref]         0702af4e71b93c9426d81a4ee4696101c7d62a84 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 0702af4 Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild